Double-transformer self-oscillation type half-bridge driving voltage-multiplying conversion circuit

Abstract

The invention provides a double-transformer self-oscillation type half-bridge driving voltage-multiplying conversion circuit. The circuit comprises an EMI filtering circuit, an LDO voltage stabilization circuit, a half-bridge conversion circuit and an output rectification and filtering circuit which are connected with one another sequentially; the circuit further comprises a half-bridge driving circuit connected with the half-bridge conversion circuit; the half-bridge driving circuit includes a secondary winding T2, an upper tube triggering circuit and a lower tube triggering circuit, whereinthe secondary winding T2 belongs to a feedback type transformer E2; and the half-bridge conversion circuit comprises a half-bridge power switching tube circuit, the primary winding T1 of the feedbacktype transformer E2, a main transformer E1 and a half-bridge capacitor bridge arm circuit. According to the circuit, a working process in which the switching-off process of one transistor starts the switching-on process of the other transistor is controlled through the saturation of the feedback type transformer E2, and therefore, current spikes which occur when switching tubes are switched on andoff are eliminated, a power transformer is higher in efficiency and low in power consumption, and therefore, the main power transformer will not enter a saturation state, and damage to the switchingtubes due to output switching power can be almost avoided.

Description

technical field [0001] The invention relates to a DC-DC switching power supply, in particular to a double-transformer self-excited oscillation type half-bridge driving voltage doubler conversion circuit. Background technique [0002] At present, in industrial automation control, rail-mounted signal isolators are widely used. In traditional rail-mounted signal isolators, most of the regulated power supplies use push-pull self-excited conversion circuits. Due to the low efficiency, high power consumption, large ripple and noise interference of the circuit with this control method, it is difficult to solve the problem. The output switching power of the push-pull conversion circuit has high requirements on the tube. If the matching is not good, the parameters of the power switch will be inconsistent. Or the asymmetry causes the unidirectional magnetic bias phenomenon of the high-frequency transformer magnetic core, which in turn causes the saturation of the magnetic core and dam...

AI Technical Summary

Problems solved by technology

Due to the low efficiency, large power consumption, large ripple and noise interference of the circuit with this control method, it is difficult to solve the problem. The output switching power of the push-pull conversion circuit has high requirements on the tube. If the matching is not good, the parameters of the power switch will be inconsistent. Or asymmetry causes the unidirectional magnetic bias phenomenon of the high-frequency transformer core, which in turn causes the saturation of the core and causes damage to the tube by the output switching power

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